Did you lease from a reputable property manager that has a storefront?
Do you have an address where to mail the payments or a person whom to deliver them?
No reputable property manager will lease a property that has been foreclosed (and if there was any exception it has to be clearly disclosed). Monthly payments must be done at the property management office, so you have proof it was delivered.
With the little info you provided it does sound like a scam. Verify with any real estate if the property is listed for sale with a RE broker. If not, then contact Fannie Mae directly. If a scam you will need to make a police report. And maybe make a call to the to the Channel 9 investigative reporter...they may be able to find you some answers.
Lots of cash required up front is usually a red flag
Here is what I would do. Open the phonebook under Real Estate and call a couple offices and ask the person answering the phone to check the ownership of a property for you. Explain it to them and see if they can access public records (many counties have this ability) to see who owns it. If it comes back as bank owned then find your landlord and question them.